Ritchie Coster and Leon Addison Brown. Photo by Richard Termine

But if the toxic intermingling of compassion and desolation of this setting, which was designed by Christopher H. Barreca and apocalyptically lit by Stephen Strawbridge, is an ideal one given the circumstances, Fugard's play has considerable trouble living up to it. Under the playwright's own direction, The Train Driver comes across as little more than a compelling idea that never makes the best possible case for itself. You walk away from the 95-minute, intermissionless evening impressed by its ambition, but left empty by its refusal to tackle head on its most suffocating issue: guilt.

Fugard has effortlessly locked into his expression of South Africa two decades after apartheid, which he spent a significant portion of his career railing against onstage, collapsed and set the country on the path to some sort of unity. (The play is set in 2010.) In doing so, he makes it clear that some ghosts don't depart easily, if at all, and the solutions we devise are often worse than the problems we face. His prime instrument for that here is the title character, Roelf Visagie (Ritchie Coster), a middle-aged white man who was unable to stop his speeding train from killing a black woman and her baby when they stepped onto the tracks. In the time since the tragedy, he's been able to forgive himself, let alone comprehend what she must have been thinking in her final moments.

So he's arrived at the graveyard in the Shukuma squatter camp, on the outskirts of Port Elizabeth, to find her remains and hopefully attain the necessary closure. But the attendant, the black Simon Hanabe (Leon Addison Brown), doesn't know where he buried her. He, after all, seen hundreds of such people—all he can do is his job. Roelf steps over his attempts to do that now, and tries to derive from Simon the validation he needs, even if, as seems increasingly likely, there's none there to be found.

It's a powerful setup based on real-life events, and one can see how it would lead to what Fugard has said he considers the most important play he's ever written. Unfortunately, the payoff is lacking. Fugard has proven he can weave considerable magic from a tiny collection of racially divergent characters—his two previous Signature productions this season, Blood Knot and My Children! My Africa!, proved as much just by themselves—but only if they share a passion and a voice. Here they don't: Roelf feels whole, waging a vicious war against himself for the kinds of insubstantial reasons that human frailty elevates to too-grand importance, but Simon is at best a device for letting Roelf unleash his uncertainty-choked views without ever landing any blows of his own in return.

Fugard's staging is simple and stark, drawing little attention to itself: a universe that's no more than these two men choose to make it. But without solid materials to construct from, anything they build will be shaky. Through no fault of Brown, who is excellent at portraying an eroded sense of inevitability, Simon is illusive and intractable, more about conveying platitudes than he is representing the world Roelf is convinced he's destroying. Coster has some trouble negotiating the difficult Afrikaaner accent he's using, leading to a number of lines that don't land as clearly as they should, but he projects a crumbling dark force that yanks you into Roelf's unfathomable mind and thrusts upon you the corrosive rage, sorrow, and helplessness that characterize him.

That's exactly right, but it's only half of what we need. Without a more thorough exploration of the lot of South Africa's poor blacks, there's not a lot of meat here. We can't know for sure, of course, what drove the young woman to not only kill herself but also her helpless child, and that's part of the point: Sometimes that's all we have to live with. But Simon provides us a way to explore, or at least view, these implications, if in a more roundabout way. Fugard's refusal to take advantage of that avenue leaves us wondering too many things, and without the clarity or purpose that defined so many of his other plays, which were equally ambiguous in structure but more sharply profound in execution. Like Roelf, we want to believe there's something greater at work. But without additional evidence, The Train Driver too often seems to be merely spinning its wheels.

The Train Driver
Through September 23
Signature Theatre Company's Romulus Linney Courtyard Theatre at the Signature Center, 480 West 42nd Street between Dyer and 10th Avenues
Running Time: 90 minutes with no intermission
Tickets and current schedule signaturetheatre.org